Ordinary and Preference Shares - Additional Information (Detail) - USD ($) $ / shares in Units, $ in Millions		3 Months Ended	6 Months Ended
	Sep. 15, 2020	Sep. 30, 2020	Sep. 30, 2020	Jan. 29, 2015
Class Of Stock [Line Items]
Subscriptions price, per share				$ 22.50
Ordinary Shares [Member]
Class Of Stock [Line Items]
Issue of shares, net of issue costs, Shares	20,294,117	20,294,117	20,294,117
Newly issued ordinary price per share	$ 4.25
Proceeds from issuance of ordinary shares	$ 86.3
Underwriting discounts and other offering expenses	$ 5.6